"An attorney has filed a federal lawsuit, which is very serious, and he is making some serious allegations about sexual assault," civil litigator Anahita Sedaghatfar, an expert in sexual harassment cases, tells E! News.

"I'm actually very concerned for [the plaintiffs' attorney, Okorie Okorocha] and I hope that he has thoroughly vetted his clients. I hope he has evidence to back up his claims."

"Marty is known as a pit bull for a reason," Sedaghatfar says. "He has a stellar record. And that is why time after time celebrities in trouble go to him."

In this case, Singer has already publicly stated that Travolta is not in trouble because he wasn't in California when John Doe No. 1 claims in the lawsuit the actor tried to manhandle him during a massage appointment in Beverly Hills, and that the additional claims of John Doe No. 2—that Travolta exposed himself and groped the masseur during a session in his Atlanta hotel room—are just as "absurd and ridiculous as the first one."

Sedaghatfar tells E! News that if it were her client being sued, she would first ask the plaintiffs, "Where is the police report?" (A criminal complaint does not have to be filed before a civil suit.)

"If this goes down the way Marty Singer says it will, I think Mr. Okorocha is in big trouble, I really do," Sedaghatfar says of the John Does' attorney.

"For Marty to go out on the record and confidently say that he believes he can get the case thrown out, I think is something he wouldn't say unless he had the evidence to present to the judge to achieve that."

Singer said in a statement to Radar Online today: "The problem in America is anyone can sue anyone. However in this case this unidentified plaintiff and his lawyer will regret they filed this fabricated suit. We intend to sue both of them for malicious prosecution."

Travolta, who has two children with his wife of 21years, Kelly Preston (son Jett died in 2009), has denied stories that have implied he's anything other than heterosexual. He toldRolling Stone in 1983 that "everybody" is the subject of a rumor about being gay at one time or another.

"That's a notorious rumor," the Grease star said. "They say that about me, Marlon Brando, every male, epecially the first year that you become a star."

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